Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Help me decipher what are the function of pins on LCDs

Not open for further replies.


Advanced Member level 3
Apr 12, 2005
Reaction score
Trophy points
Activity points


First of all, I'd like to say : MERRY Christmas & Happy new Year

I have 2 LCDs, I got them from broken telephone sets. I can't understand what are the function of each pin. I couldn't find any datasheet for them.
The 2 LCDs are different.

I'll really appreciate your help.


Re: LCD Help ..... plz

They seem to be specifically build for telephone sets. HK or HKS may refer to the hook switch. Others signals as SDI and ClK suggest a serial interface. And 12/24 the time format for the clock display.
It is strange that in the 2nd photo there is no VSS connected.
I would try to follow the connections of the LCDs to the phone sets. If you have an oscilloscope you can check what is going on on the serial data lines. If a scope is not available you can use a simple logic analyzer that uses the parallel port of a pc.

Re: LCD Help ..... plz

check for datasheets on the internet

LCD Help ..... plz

Thanks for your replies, but what about the other pins.???

Could anyone tell me, How to do the following:
" I want to activate the lcd and send any digit to it using a microcontroller. I think SD1 or D1 are for the data."

Thanks again for your help.

LCD Help ..... plz

You are going to have to check for a part number on them then locate a data sheet online.

VDD should be power and CLK would be your clock input.

LCD Help ..... plz

Thanks for all your help,.. But, as I told you before that there's nothing written except that in the pictures.
Could anyone guide me to a reference, where I can find info about these terminals.???

Thanks again. :D

Re: LCD Help ..... plz

Hi seadolphine2000,

Check if inside broken telephone sets you got one stamped HT93 followed by two or three digits (the dialer part of telephone). If yes you probably have one of Holtek HT1613 or HT1616 depends of the number of LCD digits (8, 10, 12, 16)
**broken link removed** page 9
**broken link removed** page 8
**broken link removed**
Not open for further replies.

Part and Inventory Search

Welcome to